The invention relates to a dental X-ray diagnostic installation for producing panoramic tomograms of the jaw of a patient. The apparatus contains a rotary unit arranged on a carriage of a stand comprising a carrier which rotates on an axis, a radiation source and a film cassette are mounted on the carrier diametrically relative to the axis with the cassette being adjustably held so that the rays coming from the radiation source impinge on the film cassette essentially perpendicular. The apparatus also includes an adjustment mechanisms with which the carrier can be adjusted in an orbit curve corresponding to a dental arch of the patient.
A known apparatus of the dental X-ray diagnostic device is a ORTHOPANTOMOGRAPH 10 which is disclosed in a brochure entitled "ORTHOPANTOMOGRAPH 10, M-D 80/1361; WS 08832". In this known device, the rotary unit contains a horizontally carrying beam whose one end accepts the radiation source and the other end accepts the film cassette holder coupled to a special mechanism so that the film cassette is stationarily inserted in the film cassette holder without any adjustments. The mechanism is thereby designed so that the film cassette holder is adjusted relative to the radiation source with a definite speed which is synchronized with the running speed of the radiation source in the course of the rotational movement of the carrier around the patient head.
The adjustment mechanism that is required in order to adjust the rotary unit in the orbital curve corresponding to the dental arch is comparatively complicated and is relatively involved in terms of its mechanical design. This is particularly true in order to achieve the required matching of the motion sequences of the rotary unit on the one hand and of the film cassette mount on the other hand.